package advance_1;

import java.util.Arrays;

public class SysTest {
    public static void main(String[] args) {
        System.out.println();
        long time=System.currentTimeMillis();
        System.out.println(time+"从1970到现在的毫秒数");
        System.out.println(System.getenv());
        System.out.println(System.getProperties());
        System.out.println(">>>>>>>>>>>>>>>>>>>..");
        long start=System.nanoTime();//纳秒
        int a=120790*666;
        long end=System.nanoTime();
        System.out.println(end-start);
        System.out.println(">>>>>>>>>>>>>>>>>");
        //???System.arraycopy();
        int a1[]={1,3,5,7,9};
        int a2[]=new int[20];
        System.arraycopy(a1,2,a2,4,3);
        System.out.println(Arrays.toString(a2));
    }
}
